Icon of the Defender

The Icon of the Defender is an artifact from Hexen. It has the shape of a miniature gray castle tower, similar to the in, with a purple aura. It grants almost total invulnerability to all classes; however, the precise effect differs for each character: The effect lasts for 30 seconds.
 * The Fighter gets no secondary effect and is simply rendered invulnerable, an effect similar to Doom's invulnerability artifact and Heretic's Ring of Invincibility, except that the player's view is not affected.
 * The Cleric phases between partial and total invisibility. Whilst completely invisible, projectiles can travel straight through the player.
 * The Mage deflects incoming projectiles away from his body. As with the Disc of Repulsion, seeking projectiles deflected in this manner are considered to be controlled by the mage and will seek his enemies.

Instant death effects such as telefragging or falling damage from great heights (2047+ units of uninterrupted freefall) will still kill a player using the icon.

Appearance statistics
In the IWADs the icon of the defender is first encountered on these maps per skill level:

The IWADs contain the following numbers of icons of the defender per skill level:

Other games
The same item reappears in Hexen II. Heretic has a similar item - Ring of Invincibility.